The broad objective of a cooperative oncology group using sophisticated statistical and biomedical methods is to evaluate rapidly the effectiveness of potential anti-neoplastic agents and treatment modalities in humans with malignant disorders. Other objectives are to assess the relative value of a drug, drug combinations, drugs plus radiation therapy, and immunotherapy in cancer therapy of advanced disease, and to apply these methods when proven successful to the adjuvant therapy of early cancer with curative intent. Cooperative groups also serve as a forum for exchange of ideas among investigators, provide training for young physicians in the principles of clinical research in human neoplasms, and disseminate knowledge gained from the cooperative group studies through teaching and publications.